Birders in Rockland had the good fortune a few days ago to discover a very rare bird in Maine: a common gull. Yes, we know that seems like an oxymoron. Gulls of several species here in Maine could be called “common.” There are the ubiquitous herring gulls that most people refer to as  “seagulls” even though they are seen across much of inland Maine, often far from any marine waters. Great black-backed gulls are pretty “common,” too, especially along the coast. And ring-billed gulls are often quite numerous—we saw hundreds at Wharton Point in Brunswick earlier this fall.

But the actual bird known as the common gull is not at all common in North America. It is common across much of Europe and Asia. Up until a few years ago, it was considered a subspecies of what was then called the mew gull. What we called the mew gull included a subspecies that occurred across western North America. That form is now considered a separate species called the short-billed gull.

The common gull is a slightly smaller look-alike to the familiar ring-billed gull. While it has the same gray back, black wing tips, and yellow legs of a ring-billed gull, its bill is smaller and, in adult plumage, doesn’t have the full black ring. If you’re close enough to see it, the eye is dark rather than yellow, too. For those who want to really study, there are a variety of other features that also set it apart from the ring-billed gull.

Common gulls naturally colonized Iceland from Europe starting in the 1930s and 1940s and are reasonably common there now. We wonder if they will follow the pattern of lesser black-backed gulls that colonized Iceland in the 1920s then began breeding in Greenland in the 1980s.

Lesser black-backed gulls were once very rare birds in eastern North America but there’s a wintering population thought to number in the thousands in the mid-Atlantic region. Here in Maine, lesser black-backed gulls are seen quite regularly in fall and spring migration. Presumably, these are individuals from the Greenland breeding population.

Common gull sightings across eastern North America seem to be on the increase, which leads us to wonder if a population is already or will soon start nesting in Greenland.

Interestingly, birders discovered that there are now two common gulls in Rockland. One of them is banded. Hopefully someone will be able to document the band numbers of the banded bird and find out where it came from. That will be fascinating to know!

As so often happens when a bunch of birders convene in one place, another oddity was discovered while they were looking for the gull: a yellow-breasted chat. And late-breaking news was that a rufous hummingbird was found down in Tenant’s Harbor. Earlier today our own brother (and brother-in-law) Andrew sent photos of what looks like an immature oriole that showed up at his feeder in Georgetown.

There’s some interesting birds out there! Look closely and keep the camera handy!

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology and Vice President of Boreal Conservation for National Audubon. Dr. Wells is one of the nation's leading bird experts and conservation biologists. He is a coauthor of the seminal “Birds of Maine” book and author of the “Birder’s Conservation Handbook.” His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the popular books, “Maine’s Favorite Birds” (Tilbury House) and “Birds of Aruba, Bonaire, and Curaçao: A Site and Field Guide,” (Cornell University Press).